DOCSP-49813-Clarify-impact-scope-of-notablescan (#12257)

* DOCSP-49813-Clarify-impact-scope-of-notablescan

* External review feedback

Author: mmaville-mdb

content/manual/upcoming/source/reference/parameters.txt

@@ -1379,18 +1379,19 @@ General Parameters
 
    |mongod-only|
 
-   Specify whether **all** queries must use indexes. If ``1``, MongoDB
-   will not execute queries that require a collection scan and will return an
-   error.
+   Prevents running some collection scans when an index could be used, whether 
+   present or not. If ``true``, MongoDB will not execute queries that require
+   a collection scan and will return an error. Exclusions include queries 
+   without filters and queries against capped collections, such as the oplog.
 
-   Consider the following example which sets :parameter:`notablescan` to ``1``
+   Consider the following example which sets :parameter:`notablescan` to ``true``
    or true:
 
    .. code-block:: javascript
 
-      db.adminCommand( { setParameter: 1, notablescan: 1 } )
+      db.adminCommand( { setParameter: 1, notablescan: true } )
 
-   Setting :parameter:`notablescan` to ``1`` can be useful for testing
+   Setting :parameter:`notablescan` to ``true`` can be useful for testing
    application queries, for example, to identify queries that scan an
    entire collection and cannot use an index.